Summary At 2005 eastern daylight time, a Robinson R22 Mariner helicopter, serial number1071M, with only the pilot on board, departed Lindsay, Ontario, for the Toronto / Buttonville Municipal Airport. At 2022, a Cessna170, serial number26290, took off on Runway18 from a private grass strip, locally known as Sandford Field, with only the pilot on board. The pilot planned to conduct one left-hand circuit and landing. At 2025, the two aircraft collided in visual meteorological conditions at approximately 700feet above ground level. The accident occurred near Uxbridge, over a farmer's field one nautical mile south of Sandford Field. The helicopter's tail and the main-rotor system sustained catastrophic damage, rendering the helicopter uncontrollable. The helicopter pitched inverted and plunged to the ground, and the pilot was fatally injured. The Cessna 170sustained substantial damage; however, the pilot was able to control the aircraft and conduct a forced landing in a nearby cornfield. Ce rapport est galement disponible en franais. Other Factual Information The helicopter pilot planned to fly to the Toronto / Buttonville Municipal Airport for fuel before continuing to a private helicopter pad at the Toronto harbour. After liftoff, the pilot took up a heading of approximately 230 magnetic. The flight path of the helicopter was reconstructed from ground eyewitness reports, impact and collision marks, and an analysis of the accident debris field. After take-off, the Cessna pilot climbed out at 70mph on a southerly heading, establishing his aircraft on a 50 intercept angle with the helicopter. He did not see the helicopter until the Cessna was climbing through 700feet above ground level (agl) and the helicopter was at his 11o'clock position at very close range. The Cessna pilot initiated evasive action to the right immediately before impact with the helicopter. The Cessna170 was in a climbing, right-banked attitude at impact. The helicopter was reported to be in straight and level flight at the time of the collision. The Toronto Area Control Centre radar did not record the flight paths of the helicopter or the Cessna before the collision. The Cessna's twin-bladed, variable-pitch, constant-speed propeller was severely damaged from the impact with the helicopter's tail and main rotor. One propeller blade was severed in half perpendicular to the leading edge. The remaining blade sustained a trailing-edge radial cut, 5.5cm deep, at the midpoint of the propeller blade. The propeller spinner separated from the aeroplane. The propeller hub was severely damaged, compromising the variable-pitch system's oil reservoir. Airframe vibration was significant, and the Cessna's windshield became contaminated with oil, dramatically reducing pilot visibility. The Cessna pilot realized that the aircraft was not capable of returning to the runway and elected to execute a forced landing into a cornfield one nautical mile south of the departure runway. At 2000 eastern daylight time,1 the weather observation taken at the Toronto / Buttonville Municipal Airport was reported as follows: a few clouds at 16000feet agl, thin broken clouds at 24000feet agl, visibility 15statute miles, temperature 20C, dew point 9C, wind from 140 true at 2knots, and altimeter setting 30.18inches of mercury.2 The helicopter pilot had been a pilot for 25 years. He held a valid medical certificate and a Canadian commercial pilot licence - helicopter endorsed for BH06, HU30, HU50, RH22, and SK76helicopters and a current Group4 instrument rating. He also held a commercial pilot licence - aeroplane and a current Group1 instrument rating. In addition, he had held a Canadian glider pilot licence since 1992. The pilot was a well-known local flying enthusiast who, during the past 12years, had been a frequent performer at air shows. He had accumulated more than 948total flight hours, 688 of which were on rotary wing aircraft. During the previous 90days, he had flown 74hours, approximately 2 of which were flown on the day of the occurrence. The Cessna pilot began flying lessons in 1978 but had not completed his flight training or undergone a flight test to obtain a pilot licence. His Canadian student pilot permit had expired in October 1995, and his aviation medical certificate had expired in August 1995. He had accumulated approximately 250total flight hours at a rate of 10 to 20hours per year. The Robinson R22 Mariner helicopter, equipped for visual flight rules (VFR) operations, was manufactured in 1989 and had accumulated 2190hours. Records indicate the helicopter was equipped and maintained in accordance with regulations. The helicopter had no known defects before the flight, and its weight and centre of gravity were within approved limits. The helicopter was equipped with a functioning two-way VHF (very high frequency) radio and a transponder. The Cessna 170 was manufactured in 1954 and had accumulated 3535 hours as of November 1997, the date of the last recorded flight. Since then, no entries had been recorded. The Cessna pilot had owned the occurrence aircraft for 12years. The Cessna's certificate of airworthiness had expired on 06September 1999. Since then, the aircraft had not been inspected or maintained in accordance with Transport Canada regulations. The aeroplane had no defects or nonstructural restrictions to visibility through the front, back, or side windows. It was equipped with a VHF radio, but the pilot had not used it during the occurrence flight and regulations did not require its use. The collision occurred at approximately 700feet agl in Canadian ClassG airspace. Section2.8.7 of Rules of the Air and Air Traffic Services (RAC) in Aeronautical Information Publication (AIP) defines ClassG airspace as all uncontrolled domestic airspace within which air traffic control (ATC) has neither the authority nor the responsibility for exercising control over air traffic. There is no requirement for pilots to make mandatory position or traffic advisory calls on a common VHF radio frequency or even to have a radio on board the aircraft. There is no requirement to have a transponder or any kind of collision-avoidance instrumentation installed in the aircraft. For aircraft en route in Class Gairspace, AIP RAC8.10 advises: When aircraft are manoeuvring in the vicinity of uncontrolled aerodromes or cruising in ClassG airspace, the lack of information on the movements of other aircraft operating in close proximity may occasion a potential hazard to all concerned. To alleviate this situation, all pilots are advised that when operating in ClassG airspace, they should continuously monitor frequency126.7 MHz whenever practicable.